A user story is a concise description of desired functionality expressed from the perspective of a user or stakeholder. Agile teams commonly use stories to represent small units of value that can be discussed, refined, estimated and delivered.
User stories are common in Scrum environments, but they are not required by Scrum itself. The Scrum Guide refers more generally to Product Backlog items.
The common user story format
A common structure expresses the user, the desired capability and the reason the capability provides value.
The value of the format is not the sentence itself. The purpose is to keep planning centered on who needs the capability, what outcome is desired and why the work matters.
A user story is not a complete specification
A story should encourage discussion rather than attempt to replace every technical requirement, interface definition or acceptance document.
Complex systems may still require specifications, interface control documents, cybersecurity requirements, verification criteria and formal engineering artifacts.
Acceptance criteria
Acceptance criteria describe conditions that should be satisfied before a particular item is accepted. They reduce ambiguity and clarify expected behavior.
Acceptance criteria are more specific to an individual item than the team’s overall Definition of Done.
See Definition of Done vs Acceptance Criteria.
User stories and estimation
Teams may estimate stories using hours, relative sizing or story points. Scrum does not require a specific estimation technique.
If story points are used, planners should remember that they are relative team estimates rather than direct calendar-duration values.
User stories in an IMS
Most user stories do not belong as individual activities in a program-level IMS. Hundreds or thousands of story-level activities can make the schedule difficult to maintain without improving program-level visibility.
A stronger approach is to aggregate story execution into meaningful capabilities, releases, integration activities and milestones while preserving traceability to the Agile delivery tool.
